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1.
Opt Express ; 27(18): 25142-25153, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31510392

RESUMO

Forced oscillation based on self-injection locked phase-locked (SILPLL) opto-electronic oscillator (OEO) technique is the basis of highly stable and low phase noise oscillators to be used as a key component in modern communication and sensing systems. To avoid large-size modular OEO, inter-modal oscillation at X-band frequencies is achieved in a compact multi-mode multi-section semiconductor laser using InP foundry service. Self-forced oscillation technique of SILPLL is demonstrated, where a phase noise performance of -98 dBc/Hz is measured at 10 kHz offset carrier of 11 GHz, which is an improvement of 68 dB compared with the free-running condition, which corresponds with 600 times reduction in calculated timing jitters from the free-running case to reach 0.45 ps for over 1 kHz to 1 MHz bandwidth.

2.
Hum Factors ; 61(7): 1066-1076, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30817234

RESUMO

OBJECTIVE: The aim of this study was to analyze finger strength and effects of muscle fatigue on the ability to shoot. BACKGROUND: The finger and hand muscles of soldiers are subject to high loads. For example, the trigger pull of military pistols can amount up to 58 N (≈6 kg) and could cause muscle fatigue in the trigger finger. For soldiers, however, maintaining the ability to shoot is essential for self-defense and survival. METHOD: The marksmanship training of 30 German soldiers (15 female) ages 18 to 40 years was evaluated. Three consecutive exercises with a total of 60 rounds were fired from target ranges of 5 and 10 m, equally using a single-action and double-action trigger mode. Maximum voluntary isometric contraction of the index finger (MVCIF) was measured before and after each of the three firing exercises. RESULTS: Shooting reduced MVCIF in female (88.2 ± 15.8 N to 67.3 ± 17.7 N, p < .001) and male soldiers (145.8 ± 21.7 N to 112.7 ± 26.6 N, p < .001). Of the 30 subjects, 23 were unable to shoot due to fatigue, including 15 of 15 female soldiers. The higher MVCIF was at rest, the less commonly (r = .73, p < .001) and the later (r = 0.82, p < .001) task failure occurred. Two intermissions of approximately 6 min did not suffice for a significant recovery. CONCLUSION: Excessive trigger pull weight causes muscle fatigue of the index finger and can ultimately lead to task failure during pistol marksmanship training. Short breaks are insufficient for the recovery of finger muscles. APPLICATION: This study presents a new perspective on ideal trigger pull weight, which should be carefully considered by manufacturers to allow repetitive firing and simultaneously ensure safe handling.


Assuntos
Dedos/fisiologia , Armas de Fogo , Fadiga Muscular/fisiologia , Adolescente , Adulto , Ergonomia , Feminino , Humanos , Contração Isométrica/fisiologia , Masculino , Militares , Músculo Esquelético/fisiologia , Análise e Desempenho de Tarefas , Adulto Jovem
3.
JCI Insight ; 3(23)2018 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-30518693

RESUMO

BACKGROUND: Metformin reduces plasma glucose and has been shown to increase glucagon-like peptide 1 (GLP-1) secretion. Whether this is a direct action of metformin on GLP-1 release, and whether some of the glucose-lowering effect of metformin occurs due to GLP-1 release, is unknown. The current study investigated metformin-induced GLP-1 secretion and its contribution to the overall glucose-lowering effect of metformin and underlying mechanisms in patients with type 2 diabetes. METHODS: Twelve patients with type 2 diabetes were included in this placebo-controlled, double-blinded study. On 4 separate days, the patients received metformin (1,500 mg) or placebo suspended in a liquid meal, with subsequent i.v. infusion of the GLP-1 receptor antagonist exendin9-39 (Ex9-39) or saline. During 240 minutes, blood was sampled. The direct effect of metformin on GLP-1 secretion was tested ex vivo in human ileal and colonic tissue with and without dorsomorphin-induced inhibiting of the AMPK activity. RESULTS: Metformin increased postprandial GLP-1 secretion compared with placebo (P = 0.014), and the postprandial glucose excursions were significantly smaller after metformin + saline compared with metformin + Ex9-39 (P = 0.004). Ex vivo metformin acutely increased GLP-1 secretion (colonic tissue, P < 0.01; ileal tissue, P < 0.05), but the effect was abolished by inhibition of AMPK activity. CONCLUSIONS: Metformin has a direct and AMPK-dependent effect on GLP-1-secreting L cells and increases postprandial GLP-1 secretion, which seems to contribute to metformin's glucose-lowering effect and mode of action. TRIAL REGISTRATION: NCT02050074 (https://clinicaltrials.gov/ct2/show/NCT02050074). FUNDING: This study received grants from the A.P. Møller Foundation, the Novo Nordisk Foundation, the Danish Medical Association research grant, the Australian Research Council, the National Health and Medical Research Council, and Pfizer Inc.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Metformina/farmacologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália , Glicemia/efeitos dos fármacos , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Prandial
4.
Diabetes Obes Metab ; 20(2): 362-369, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28786523

RESUMO

AIMS: Discovery of the specific bile acid receptors farnesoid X receptor (FXR) and Takeda G protein-coupled receptor 5 (TGR5) in enteroendocrine L cells has prompted research focusing on the impact of bile acids on glucagon-like peptide-1 (GLP-1) secretion and glucose metabolism. The aim of the present study was to assess the GLP-1 secretory and gluco-metabolic effects of endogenously released bile, with and without concomitant administration of the bile acid-sequestering resin, sevelamer, in patients with type 2 diabetes. MATERIALS AND METHODS: We performed a randomized, placebo-controlled, double-blinded cross-over study including 15 metformin-treated patients with type 2 diabetes. During 4 experimental study days, either sevelamer 3200 mg or placebo in combination with intravenous infusion of cholecystokinin (CCK) (0.4 pmol sulfated CCK-8/kg/min) or saline was administered in randomized order. The primary endpoint was plasma GLP-1 excursions as measured by incremental area under the curve. Secondary endpoints included plasma responses of glucose, triglycerides, insulin, CCK, fibroblast growth factor-19 and 7α-hydroxy-4-cholesten-3-one (C4). In addition, gallbladder dynamics, gastric emptying, resting energy expenditure, appetite and ad libitum food intake were assessed. RESULTS: CCK-mediated gallbladder emptying was demonstrated to elicit a significant induction of GLP-1 secretion compared to saline, whereas concomitant single-dose administration of the bile acid sequestrant sevelamer was shown to eliminate the acute bile acid-induced increase in plasma GLP-1 excursions. CONCLUSIONS: Single-dose administration of sevelamer eliminated bile acid-mediated GLP-1 secretion in patients with type 2 diabetes, which could be explained by reduced bile acid stimulation of the basolaterally localized TGR5 on enteroendocrine L cells.


Assuntos
Ácidos e Sais Biliares/antagonistas & inibidores , Quelantes/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Células Enteroendócrinas/efeitos dos fármacos , Fármacos Gastrointestinais/uso terapêutico , Peptídeo 1 Semelhante ao Glucagon/antagonistas & inibidores , Sevelamer/uso terapêutico , Idoso , Ácidos e Sais Biliares/metabolismo , Colagogos e Coleréticos/administração & dosagem , Colagogos e Coleréticos/farmacologia , Estudos Cross-Over , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/metabolismo , Método Duplo-Cego , Quimioterapia Combinada , Células Enteroendócrinas/metabolismo , Feminino , Esvaziamento da Vesícula Biliar/efeitos dos fármacos , Esvaziamento Gástrico/efeitos dos fármacos , Peptídeo 1 Semelhante ao Glucagon/sangue , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Humanos , Hipoglicemiantes/uso terapêutico , Infusões Intravenosas , Masculino , Metformina/uso terapêutico , Pessoa de Meia-Idade , Sincalida/administração & dosagem , Sincalida/farmacologia
5.
J Clin Endocrinol Metab ; 102(11): 4153-4162, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28938439

RESUMO

Context: Despite a position as the first-line pharmacotherapy in type 2 diabetes, the glucose-lowering mechanisms of metformin remain to be fully clarified. Gut-derived modes of action, including suppression of bile acid reabsorption and a resulting increase in glucagon-like peptide-1 (GLP-1) secretion, have been proposed. Objective: The aim of this study was to assess the GLP-1 secretory and glucometabolic effects of endogenously released bile, with and without concomitant single-dose administration of metformin in patients with type 2 diabetes. Design: Randomized, placebo-controlled, and double-blinded crossover study. Setting: This study was conducted at Center for Diabetes Research, Gentofte Hospital, Denmark. Patients: Fifteen metformin-treated patients with type 2 diabetes; all participants completed the study. Interventions: Four experimental study days in randomized order with administration of either 1500 mg metformin or placebo in combination with intravenous infusion of cholecystokinin (0.4 pmol × kg-1 × min-1) or saline. Main Outcome Measure: Plasma GLP-1 excursions as measured by baseline-subtracted area under the curve. Results: Single-dose metformin further enhanced bile acid-mediated induction of GLP-1 secretion (P = 0.02), whereas metformin alone did not increase plasma GLP-1 concentrations compared with placebo (P = 0.17). Metformin, both with (P = 0.02) and without (P = 0.02) concomitant cholecystokinin-induced gallbladder emptying, elicited reduced plasma glucose excursions compared with placebo. No GLP-1-mediated induction of insulin secretion or suppression of glucagon was observed. Conclusions: Metformin elicited an enhancement of the GLP-1 response to cholecystokinin-induced gallbladder emptying in patients with type 2 diabetes, whereas no derived effects on insulin or glucagon secretion were evident in this acute setting.


Assuntos
Ácidos e Sais Biliares/farmacologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Metformina/administração & dosagem , Idoso , Glicemia/metabolismo , Colecistocinina/farmacologia , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Esvaziamento da Vesícula Biliar/efeitos dos fármacos , Esvaziamento da Vesícula Biliar/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Placebos
6.
Dtsch Arztebl Int ; 114(26): 439-446, 2017 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-28705295

RESUMO

BACKGROUND: Women, on average, have less muscle strength than men. This anthropometric-physiological trait may make them more vulnerable to ex - cessive physical strain, injury, and inability to work. Strength training is used for preventive health maintenance and to lessen musculoskeletal symptoms. In this context, we studied whether the degree of muscle strength has any effect on women's health in everyday working life, and also the effects of strength training for women on their health in the workplace. METHODS: We systematically searched the PubMed/MEDLINE, Embase, CINAHL, Web of Science, CENTRAL, and SPOLIT databases for pertinent publications, in accordance with the PRISMA criteria for literature searches. We analyzed all of the retrieved randomized controlled trials conducted on women aged 18 to 65 to determine the effects of training on muscle strength, physical performance ability, and health-related parameters including body composition, musculo - skeletal pain, and subjective well-being. RESULTS: We did not find any studies that provided answers to the first question. As for the second question, the selection criteria were met by 12 of the 4969 retrieved studies, which dealt with the effect of strength training on health in the occupational environment and involved a total of 1365 female subjects. These studies were carried out in heterogeneous subject groups, with a variety of overlapping interventions consisting of both strength and endurance training. Significantly increased strength was found in all studies, as was a reduction of pain in all of the studies where this question was asked. Inconsistent results were obtained with respect to body weight, body composition, and subjective well-being. CONCLUSION: The interventions that were conducted in these studies succeeded in increasing strength and reducing pain, even when the training was brief and of low intensity. This was true not only for women working in occupations requiring unusual physical strength, but also for those in sedentary occupations. The small number of studies performed on this subject to date is surprising in view of the high prevalence of musculoskeletal symptoms in women.


Assuntos
Promoção da Saúde , Força Muscular , Treinamento Resistido , Adolescente , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Dor , Ensaios Clínicos Controlados Aleatórios como Assunto , Local de Trabalho , Adulto Jovem
7.
Artigo em Inglês | MEDLINE | ID: mdl-28060705

RESUMO

Virtually all commercial instruments for the measurement of the oscillator PM noise make use of the cross-spectrum method (arXiv:1004.5539 [physics.ins-det], 2010). High sensitivity is achieved by correlation and averaging on two equal channels, which measure the same input, and reject the background of the instrument. We show that a systematic error is always present if the thermal energy of the input power splitter is not accounted for. Such error can result in noise underestimation up to a few decibels in the lowest-noise quartz oscillators, and in an invalid measurement in the case of cryogenic oscillators. As another alarming fact, the presence of metamaterial components in the oscillator results in unpredictable behavior and large errors, even in well controlled experimental conditions. We observed a spread of 40 dB in the phase noise spectra of an oscillator, just replacing the output filter.

8.
Diabetes Obes Metab ; 19(2): 189-199, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27696668

RESUMO

AIMS: The duodenal-jejunal bypass sleeve ((DJBS) or EndoBarrier Gastrointestinal Liner) induces weight loss in obese subjects and may improve glucose homeostasis in patients with type 2 diabetes (T2D). To explore the underlying mechanisms, we evaluated postprandial physiology including glucose metabolism, gut hormone secretion, gallbladder emptying, appetite and food intake in patients undergoing DJBS treatment. MATERIAL AND METHODS: A total of 10 normal glucose-tolerant (NGT) obese subjects and 9 age-, body weight- and body mass index-matched metformin-treated T2D patients underwent a liquid mixed meal test and a subsequent ad libitum meal test before implantation with DJBS and 1 week (1w) and 26 weeks (26w) after implantation. RESULTS: At 26w, both groups had achieved a weight loss of 6 to 7 kg. Postprandial glucagon-like peptide-1 (GLP-1) and peptide YY responses increased at 1w and 26w, but only in T2D subjects. In contrast, glucose-dependent insulinotropic polypeptide responses were reduced only by DJBS in the NGT group. Postprandial glucose, insulin, C-peptide, glucagon, cholecystokinin and gastrin responses were unaffected by DJBS in both groups. Satiety and fullness sensations were stronger and food intake was reduced at 1w in NGT subjects; no changes in appetite measures or food intake were observed in the T2D group. No effect of DJBS on postprandial gallbladder emptying was observed, and gastric emptying was not delayed. CONCLUSIONS: DJBS-induced weight loss was associated with only marginal changes in postprandial physiology, which may explain the absence of effect on postprandial glucose metabolism.


Assuntos
Cirurgia Bariátrica/métodos , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Obesidade/cirurgia , Adulto , Apetite , Composição Corporal , Peptídeo C/metabolismo , Estudos de Casos e Controles , Colecistocinina/metabolismo , Comorbidade , Diabetes Mellitus Tipo 2/epidemiologia , Ingestão de Alimentos , Feminino , Esvaziamento da Vesícula Biliar , Esvaziamento Gástrico , Polipeptídeo Inibidor Gástrico/metabolismo , Gastrinas/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Hemoglobinas Glicadas/metabolismo , Humanos , Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Peptídeo YY/metabolismo , Período Pós-Prandial , Estudos Prospectivos , Resposta de Saciedade , Resultado do Tratamento
9.
Dan Med J ; 63(11)2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27808040

RESUMO

Bariatric surgery (e.g. Roux-en-Y gastric bypass (RYGB)) has proven the most effective way of achieving sustainable weight losses and remission of type 2 diabetes (T2D). Studies indicate that the effectiveness of RYGB is mediated by an altered gastrointestinal tract anatomy, which in particular favours release of the gut incretin hormone glucagon-like peptide-1 (GLP-1). The EndoBarrier gastrointestinal liner or duodenal-jejunal bypass sleeve (DJBS) is an endoscopic deployable minimally invasive and fully reversible technique designed to mimic the bypass component of the RYGB. Not only GLP-1 is released when nutrients enter the gastrointestinal tract. Cholecystokinin (CCK), secreted from duodenal I cells, elicits gallbladder emptying. Traditionally, bile acids are thought of as essential elements for fat absorption. However, growing evidence suggests that bile acids have additional effects in metabolism. Thus, bile acids appear to increase GLP-1 secretion via activation of the TGR5 receptor on the intestinal L cell. Recently FXR receptors were postulated to contribute to GLP-1 secretion too. Furthermore, metformin has been shown to increase circulating GLP-1 levels but although the exact mechanism is not fully elucidated it may involve metformin-induced inhibition of bile acid reuptake from the small intestines. Small-sized studies reported varying degrees of weight loss and, in some, improvement of glucose metabolism. Therefore, the objectives of this thesis were to collect existing information on the DJBS in order to evaluate clinical efficacy and safety (study I and II). Furthermore, since the endocrine impact of the DJBS is not fully elucidated, and DJBS is expected to mimic RYGB, we investigated postprandial metabolic changes following 26 weeks of DJBS treatment in ten obese subjects with normal glucose tolerance (NGT) and nine matched patients with T2D (study III). Finally, we studied the single and combined effects of CCK induced gallbladder emptying and single-dose metformin on human GLP-1 secretion in ten healthy subjects (study IV). We hypothesized that metformin-induced GLP-1 secretion - at least partly - would be dependent on gallbladder emptying and the presence of bile acids in the gut. DJBS appears to lead to moderate weight losses in obese subjects compared to diet or lifestyle modifications (study II). DJBS had insignificant and small effects (compared to diet) on glycaemic regulation. Adverse events consisted mainly of mild-to-moderate transient dyspepsia. Nearly 20% (n = 66) of DJBS treated subjects experienced a serious adverse event (e.g. gastrointestinal bleeding or device migration), which resulted in early device removals. No deaths or liver abscesses were reported following DJBS treatment. In our own study III we found similar, moderate weight losses as in study II. GLP-1 and PYY concentrations increased in patients with T2D (not NGT subjects) after implantation. DJBS had no or minor effects on postprandial levels of glucose, insulin, C-peptide, glucagon, GIP, CCK or gastrin. Food intake decreased in parallel with an increased sensation of satiety in obese NGT subjects, but were transient. Dyspeptic episodes occurred in nearly all participants. Five devices (21%) were explanted early due to abdominal pain, and few changes of on-going antidiabetic medication were made. Finally, study IV showed that both CCK-induced gallbladder emptying and metformin alone elicited significant GLP-1 responses that were additive upon combination. Moreover, we saw significant PYY and short-lasting glucose-dependent insulinotropic polypeptide (GIP) responses following gallbladder emptying. In conclusion, in spite of increased GLP-1 responses in patients with T2D and a modest weight loss, DJBS had no effect on postprandial glucose metabolism, and therefore no patient with T2D achieved disease remission. Based on our results, we cannot recommend DJBS to be implemented as a standard of medical care management of obese patients with T2D. Future larger trials may lead to different conclusions. In addition, the observed gut hormone responses following CCK-induced gallbladder emptying and metformin, make suggest that bile acid release into the small intestines with subsequent TGR5 and FXR involvement contributes to stimulation of GLP-1 secretion and, therefore, that metformin's mode of action encompasses both bile acid-dependent and independent stimulation of gut hormone secretion.


Assuntos
Cirurgia Bariátrica/métodos , Diabetes Mellitus Tipo 2/cirurgia , Obesidade/cirurgia , Animais , Cirurgia Bariátrica/efeitos adversos , Cirurgia Bariátrica/instrumentação , Ácidos e Sais Biliares/metabolismo , Colecistocinina/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Derivação Gástrica , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Peptídeo 2 Semelhante ao Glucagon/metabolismo , Hemoglobinas Glicadas/metabolismo , Humanos , Incretinas/metabolismo , Metformina/farmacologia , Obesidade/metabolismo , Redução de Peso
10.
J Clin Endocrinol Metab ; 101(5): 2076-83, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27003305

RESUMO

CONTEXT: Bile acids have been suggested to mediate glucagon-like peptide-1 (GLP-1) secretion. Metformin, too, has been shown to increase GLP-1 levels. The effect of gallbladder emptying, metformin, or a combination has, however, never been studied. OBJECTIVE: We hypothesized that cholecystokinin (CCK)-8-induced gallbladder emptying stimulates human GLP-1 secretion and that metformin would potentiate this effect. DESIGN: A double-blinded, randomized study. SETTING: The study was conducted at a specialized research unit. PARTICIPANTS: Ten healthy male subjects with no family history of diabetes (age, 22 [range, 20-32] years; body mass index, 21.7 [19.3-24.2] kg/m(2); fasting plasma glucose, 4.9 [4.7-5.3] mm; and glycosylated hemoglobin A1c, 5.1 [4.4-5.8] %). INTERVENTION: On 4 separate days, the subjects received metformin or placebo and a concomitant 60-minute intravenous infusion of saline or CCK. Blood was sampled for 4 hours, and gallbladder volume was measured by ultrasound. MAIN OUTCOME MEASURES: Plasma levels of GLP-1. RESULTS: CCK-induced gallbladder emptying and metformin alone (no observed effect on gallbladder emptying) both elicited significant and additive GLP-1 responses. Metformin alone or combined with gallbladder emptying elicited a significant peptide YY response. CCK-induced gallbladder emptying resulted in a short-lasting glucose-dependent insulinotropic polypeptide response independent of metformin. No effects were seen on plasma glucose, insulin, C-peptide, or gastrin. CONCLUSIONS: CCK-induced gallbladder emptying in healthy subjects elicits significant GLP-1 secretion, which can be potentiated by metformin.


Assuntos
Colecistocinina/farmacologia , Esvaziamento da Vesícula Biliar/efeitos dos fármacos , Vesícula Biliar/efeitos dos fármacos , Peptídeo 1 Semelhante ao Glucagon/sangue , Hipoglicemiantes/farmacologia , Metformina/farmacologia , Adulto , Glicemia , Peptídeo C/sangue , Método Duplo-Cego , Vesícula Biliar/diagnóstico por imagem , Gastrinas/sangue , Humanos , Insulina/sangue , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ultrassonografia , Adulto Jovem
11.
J Strength Cond Res ; 29 Suppl 11: S199-203, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26506188

RESUMO

Health and physical fitness are key factors for soldiers. Increased sedentary military work, significant sitting periods during commuting and leisure time, and unhealthy dietary habits have caused a considerable increase in the number of physically unfit soldiers. Even worse, the adoption of harmful lifestyle habits occurs increasingly earlier in life. The aim of this cross-sectional study was (a) to determine the physical fitness of young male soldiers and (b) to investigate the association between physical fitness and both the presence and frequency of the health risk factors overweight, smoking, and lack of exercise. A total of 4,553 volunteers aged 18-25 years performed the Basis Fitness Test consisting of the 3 disciplines agility (11 × 10 m shuttle sprint), strength (flexed-arm hang), and endurance (1,000-m run). The presence and frequency of risk factors were determined by means of anthropometric measures (body mass index, waist circumference) and questionnaire data. The portion of soldiers without risk factors decreased from 49.4% (18-year-olds) to 16.4% for 25-year-olds. Persons without risk factors completed the agility test in 41.1 ± 3.7 seconds, flexed-arm hang in 60.1 ± 19.7 seconds, and 1,000-m run in 235 ± 32 seconds. Physical performance in all dimensions tested (agility, strength, endurance) notably deteriorated with the sole presence of one of the risk factors overweight, smoking, and lack of exercise. Any further risk factor led to further fitness decreases (p < 0.001). Mean performances of soldiers with 3 risk factors were 46.7 ± 4.1 seconds (11 × 10 m shuttle sprint), 27.6 ± 6.4 seconds (flexed-arm hang), and 298 ± 45 seconds (1,000-m run). Impacts of unhealthy lifestyles and significant losses in physical fitness are already visible in young male soldiers. Armed Forces must intensify their efforts to maintain health and performance of their soldiers.


Assuntos
Militares , Sobrepeso/epidemiologia , Aptidão Física/fisiologia , Comportamento Sedentário , Fumar/epidemiologia , Adolescente , Adulto , Índice de Massa Corporal , Estudos Transversais , Teste de Esforço , Alemanha , Comportamentos Relacionados com a Saúde , Indicadores Básicos de Saúde , Humanos , Masculino , Força Muscular , Sobrepeso/fisiopatologia , Resistência Física , Fatores de Risco , Corrida/fisiologia , Fumar/fisiopatologia , Inquéritos e Questionários , Circunferência da Cintura , Adulto Jovem
12.
J Strength Cond Res ; 29 Suppl 11: S211-5, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26506190

RESUMO

Military fitness is defined as a hierarchical 4-level construct in the German armed forces: (a) "Fundamental/Baseline Fitness," (b) "Basic Military Fitness," (c) "Task Fitness," and (d) "Mission Fitness." "Fundamental/Baseline Fitness" is assessed with the "Basic Fitness Test." However, this test alone is not sufficient to assess readiness for the physical demands of deployments. The first part of the article describes the development of a tool mirroring the specific physiological requirements of military operations on a joint forces level. The "Basic Military Fitness Tool" (BMFT) combines 4 crucial military demands into one single timed test run performed with field uniform (5 kg), body armor (13.4 kg), and helmet (1.6 kg): (a) maneuver under fire: 130 m run with changes in direction, velocity, and body position, (b) casualty rescue: 40 m of dragging a 50 kg load, (c) load carrying: 100 m carrying of two 18 kg loads, and (d) load lifting: lifting a 24 kg load on to a 1.25 m high rack 5 times. The second part covers the first assessment of BMFT selectivity between high- and low-performing groups. Muscle mass and strength are important factors for working with loads. Thus, female soldiers are expected to need more time to complete BMFT because of their on average lower muscle mass. Eighteen female (age = 28.5 ± 6.6 years, lean body mass [LBM] = 45.0 ± 4.5 kg; mean ± SD) and 104 male soldiers (age = 30.0 ± 8.4, LBM = 64.3 ± 7.1) completed isometric strength testing (hand grip = 344.3 ± 51.4 N and 547.3 ± 79.1 N, elbow flexors = 118.9 ± 16.9 and 235.1 ± 42.0, knee extensors = 433.2 ± 87.4 and 631.4 ± 111.4) and BMFT (259.2 ± 44.0 and 150.0 ± 21.1 s). Except age, all variables differed significantly (p < 0.01) between groups.


Assuntos
Teste de Esforço/métodos , Militares , Aptidão Física/fisiologia , Adulto , Braço/fisiologia , Composição Corporal , Feminino , Alemanha , Força da Mão , Humanos , Perna (Membro)/fisiologia , Remoção , Masculino , Pessoa de Meia-Idade , Corrida/fisiologia , Fatores Sexuais , Suporte de Carga/fisiologia , Avaliação da Capacidade de Trabalho , Adulto Jovem
14.
Ugeskr Laeger ; 176(37)2014 Sep 08.
Artigo em Dinamarquês | MEDLINE | ID: mdl-25294038

RESUMO

Overweight and obesity are risk factors for several co-morbidities reducing life expectancy. Conservative treatment of obesity is generally ineffective in the long-term. Bariatric surgery has proven effective, but is associated with potential complications. Duodenal-jejunal bypass sleeve is a novel minimal invasive and fully reversible endoscopic treatment modality approved for treatment of obesity with or without concomitant type 2 diabetes. Here we review present data for the efficacy and safety of this treatment modality.


Assuntos
Cirurgia Bariátrica/métodos , Obesidade Mórbida/cirurgia , Duodeno/cirurgia , Humanos , Jejuno/cirurgia , Implantação de Prótese/métodos , Resultado do Tratamento
15.
Dtsch Arztebl Int ; 111(18): 320-7, 2014 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-24861651

RESUMO

BACKGROUND: Effective health promotion in the workplace is now essential because of the rising health-related costs for businesses, the increasing pressure arising from international competition, prolonged working lives, and the aging of the work force. The basic problem of prevention campaigns is that the target groups are too rarely reached and sustainable benefits too rarely achieved. In 2011, we carried out a broad-based health and fitness campaign to assess how many personnel could be motivated to participate in a model study under nearly ideal conditions. METHOD: 1010 personnel were given the opportunity to participate in various kinds of sports, undergo sports-medicine examinations, attend monthly expert lectures, and benefit from nutritional offerings and Intranet information during work hours. Pseudonymized questionnaires were used to classify the participants according to their exercise behavior as non-active, not very active, and very active. The participants' subjective responses (regarding, e.g., health, exercise, nutrition, and the factors that motivated them to participate in sports or discouraged them from doing so) were recorded, as were their objective data (measures of body size and strength). The duration of the study was one year. RESULTS: 490 of the 1010 personnel (48.5%, among whom 27.2% were nonactive, 44.1% not very active, and 28.7% very active) participated in the initial questionnaire and testing. By the end of the study, this figure had dropped to 17.8%; diminished participation affected all three groups to a comparable extent. A comparison of dropouts and non-dropouts revealed that older age was a stable predictor for drop-out (bivariate odds ratio [OR] 1.028, p = 0.006; multivariate OR 1.049, p = 0.009). The study participants reported beneficial effects on their health and health awareness, performance ability, psychological balance, stress perception, exercise and dietary behavior. CONCLUSION: Even under optimal conditions and with high use of staff resources, this model study (which cannot be universally implemented) did not lead to comprehensive and sustained personnel participation. This finding suggests that the currently available prevention instruments are insufficient for the effective and cost-efficient promotion of health and fitness in the workplace.


Assuntos
Promoção da Saúde/estatística & dados numéricos , Nível de Saúde , Estado Nutricional , Saúde Ocupacional/estatística & dados numéricos , Condicionamento Físico Humano/estatística & dados numéricos , Esportes/estatística & dados numéricos , Adolescente , Adulto , Idoso , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde , Comportamento de Redução do Risco , Adulto Jovem
16.
PLoS One ; 9(4): e92776, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24690768

RESUMO

In the view of transmutation of transuranium (TRU) elements, molten salt fast reactors (MSFRs) offer certain advantages compared to solid fuelled reactor types like sodium cooled fast reactors (SFRs). In the first part these advantages are discussed in comparison with the SFR technology, and the research challenges are analyzed. In the second part cycle studies for the MSFR are given for different configurations--a core with U-238 fertile, a fertile free core, and a core with Th-232 as fertile material. For all cases, the transmutation potential is determined and efficient transmutation performance for the case with thorium as a fertile material as well as for the fertile free case is demonstrated and the individual advantages are discussed. The time evolution of different important isotopes is analyzed. In the third part a strategy for the optimization of the transmutation efficiency is developed. The final aim is dictated by the phase out decision of the German government, which requests to put the focus on the determination of the maximal transmutation efficiency and on an as much as possible reduced leftover of transuranium elements at the end of the reactor life. This minimal leftover is achieved by a two step procedure of a first transmuter operation phase followed by a second deep burning phase. There the U-233, which is bred in the blanket of the core consisting of thorium containing salt, is used as feed. It is demonstrated, that transmutation rates up to more than 90% can be achieved for all transuranium isotopes, while the production of undesired high elements like californium is very limited. Additionally, the adaptations needed for the simulation of a MSFR, and the used tool HELIOS 1.10 is described.


Assuntos
Reatores Nucleares , Cloreto de Sódio/química , Urânio/química , Peso Molecular , Nêutrons , Radioisótopos
17.
BMJ Open ; 3(9): e003417, 2013 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-24038010

RESUMO

INTRODUCTION: Obese patients with type 2 diabetes undergoing bariatric surgery experience significant and lasting weight loss and improved glycaemic control. However, bariatric surgical procedures such as Roux-en-Y gastric bypass are irreversible and associated with considerable short-term and long-term risks. The EndoBarrier Gastrointestinal Liner or duodenal-jejunal bypass sleeve (DJBS) is a fully reversible procedure that has been developed to treat obesity and type 2 diabetes. We aim to perform a systematic review and meta-analysis of safety and efficacy of DJBS. METHODS AND ANALYSES: A systematic review with meta-analysis (as per the preferred reporting items for systematic reviews and meta-analyses) of randomised controlled trials of the device (vs no intervention, sham and/or low-calorie diet) will be performed. Primary endpoints include change in body weight and glycated haemoglobin and safety. Secondary endpoints constitute changes in other glycaemic parameters and blood lipids and the proportion of patients discontinuing antidiabetic medication. MEDLINE, EMBASE, The Cochrane Library and Science Citation Index will be sought electronically along with manual searches. The primary meta-analysis will use random effects models due to an expected intertrial heterogeneity. Fixed effect meta-analysis will be executed to assess the impact of small trials. Dichotomous data will be analysed using risk difference and continuous data using weighted mean differences, both with 95% CIs. ETHICS AND DISSEMINATION: The study will describe the impact of DJBS on obesity and type 2 diabetes and possibly contribute to clinical decision-making. The results of this study will be disseminated by peer-reviewed publication and scientific presentations. REGISTRATION: PROSPERO CRD42013004819.

18.
J Strength Cond Res ; 26 Suppl 2: S15-22, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22614227

RESUMO

The number of sedentary young adults has dramatically increased in past decades, and sedentary lifestyles are adopted at an increasingly earlier age. Little is known about barriers or predictors to (re)initiate regular physical activity in this group. The purpose of the study is to (a) identify subgroups in nonathletes differing in their amenability to physical exercise, (b) to analyze them for differences in barriers and intention to exercise, and (c) compare importance of sports during youth in nonathletes to trained peers. Using a health and fitness questionnaire 589 nonathletes were queried in the cross-sectional survey and compared with 270 trained peers. Athletic abstainers (A), lower (L), and higher (H) motivated nonathletes were separated based on previous engagement in sports. Of the nonathletes, 54.7% reported only 1 barrier to exercise. Although this feature was most prominent in H (71.5%), the other groups showed significantly more barriers and a broader distribution. Similar characteristics but minor differences were observed for perceived importance of sports during youth. The most significant differences between athletes and nonathletes emerged enquiring the attitude and activity of the parents. The majority of nonathletes (72.8%) indicate their intention to exercise in the future. Their intention differed significantly in H (88.1%), L (76.1%), and A (59.1%). However, there are good reasons to doubt that most of those intending nonathletes will actually become physically active. Even in the analyzed narrow age range of men different motivated groups of nonathletes were found. Because of the differences in receptiveness and approachability health promotion policies may not only consider the often recommended tailored interventions but also carefully designed incentive programs.


Assuntos
Exercício Físico/psicologia , Motivação , Esportes/psicologia , Adulto , Estudos Transversais , Promoção da Saúde , Humanos , Masculino , Atividade Motora , Aptidão Física/psicologia , Inquéritos e Questionários , Adulto Jovem
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